Electron discharge device



Oct. 21, 1947.

E. K. WIMPY ET AL ELECTRON DISCHARGE DEVICE Filed NOV. 20, 1944 INVENTORS EZ/f. W/MP Y L CUWEE/VEEL ATTORNEY Patented Oct. 21, 1947 ELECTRON DISCHARGE DEVICE Edgar K. Wimpy, Fairmont Farms, W. Va., and Leo C. Werner, Bloomfield, N. J., assignors to Westinghouse Electric Corporation, East. Pitts.- burgh, Pa... a corporation of Pennsylvania Application November 20, 1944, Serial No. 564,242

8 Claims. 1 This invention relates to electron discharge devices, and particularly to such devices having an adjustable electrode therein.

It is a known fact that even though every possible eifort is exercised in manufacture of 5- many tubes are rejected after completion which would be usable if it were possible to effect appropriat adjustment without having to disturb the vacuum seal of the device. Such a desideratum assumes greater importance in the larger sizes and more expensive types of devices such as high power amplifiers. For such use, a high mu or amplification factor is essential, and that in turn is sensitiv to variation in the grid circuit. Positional alteration of the grid has direct influence upon the grid circuit. Human skill has not attained that degree of perfection which enables grids to be manufactured and mounted invariably accurately and thus different tubes will present different impedances or other tube characteristics.

The principal object of the invention is to enable a sealed electron discharge device to have an electrode therein adjustable to improve tube characteristics of the finished device.

More specifically, an object of the invention is to provide an adjustable grid of improved character.

Another object of the invention is to provide a grid adjustable as to diameter.

Yet another object of the invention is to maintain the grid when adjusted parallel to its previous position.

Again, an object of the invention is to provide improved operating means for eifecting the grid adjustment.

Still further objects of the invention will ap-- envelope protrude a plurality of glass nipples H inthe lower ends of which are sealed the edges of thimbles or prongs l2 which constitute the exterior electrical connections for internal parts. Posts l3 of appropriate length extend from the thimbles I2 upwardly'inward of the envelope, certain of the posts carrying transverse brackets [4, which in turn support upright'rods l5, at the upper ends of which are transverse parallel bus plates or rings Hi to which the ends of filament or cathode legs I1 are secured. The several filament legs are shown ina sequential series as a cathode assembly in the form of a bird cage symmetrically disposed about a common axis which is the central axis of the device. Otherof posts l3 support an anode l8 coaxial to and at a distance from the cathode assembly;

Located in the region between the cathode assembly and the anode and coaxial therewith is a cylindrical grid assembly comprising a sequential series of longitudinal wires l9 all parallel to each other and to the axis. According to the present invention, these several grid wires are adjustable laterally; that is, in a direction radial to the axis. It is by virtue of this adjustment thatthe tube characteristics may be changed since different spacing of the grid from the other electrodes effects a change of impedance. It is a feature of the invention that these several grid wires may be moved but retain parallelism to the axis.

Mounting for the grid is accomplished by certain fixed parts and by movable parts. The fixed parts are shown as plates transverse to and centralized on the axis, one such fixed plate 20 being shown above the cathode assembly and another fixed plate 2| being shown below the cathode assembly between the bus rings l6 and brackets I4. This lower fixed plate 21 is. carried on upright rods 22 similar to previously described cathode supporting rods l5 and similarly sup ported from one of the posts l3. The upper plate 20 is shown fixed in suspended position above the cathode on an axially located rod 23 which is sealed in the upperpart. of-the en,

--velope I0.

The grid wire is stiff and therefore swinging one arm will swing the other, and thus the grid wire is shifted in a radial plane in constant parallelism to the axis.

In order to swing said arms 24 and shift all of said grid wires simultaneously and equally, each lower arm 24 has a link 25 pivotally attached at an appropriate part of the arm, for instance at the pivoting of the grid wire to the arm, the several links being pivotally connected at their other ends to a movable plate 26. As shown, said movable plate is parallel to and below lower fixed plate 2| and centered on the common axis. Both said plates 2| and 26 have suitable apertures therethrough for clearance purposes for such fixed rods l and 22 as pass therethrough.

At the middle of movable plate 26 is secured a supporting and controlling stem 2! which extends axially through the bottom of the envelope,

so that raising or lowering said stem correspondingly moves the movable plate and thereby actuates the several links which in turn swing the grid supporting arms and shift the grid wires laterally.

Said stem 21 is rendered longitudinally movable by means of a bellows seal 28, the inner end of 25 which is shown sealed to the stem and the outer end of which is shown sealed to a fixed nut 29 having external screw threads. The nut 29 is peripherally soldered to a sleeve 30 situated around the bellows, said sleeve being sealed to the glass envelope. Overlying the threaded surface of the nut is a rotatable and internally threaded cap 3|. Said stem is mounted rotatably through the transverse end wall of said cap and is shouldered at 32' to have bearing against the inside of said wall and has a collar 33 on the outside of said wall necessitating that the cap and stem move longitudinally together. By virtue of the threaded engagement of the cap with the fixed nut 29, rotation of the cap obtains longitudinal adjustment of the stem, which, as explained above, obtains the desired lateral adjustment of the grid wires.

We claim:

1. An electron discharge device comprising an evacuated envelope, a cathode, grid and anode in said envelope, said grid having wires parallel to and substantially equidistant from the cathode axis, adjustable means mounting said wires movably for movement toward and away from the cathode and its axis and mounted to maintain said wires substantially in constant parallelism and to simultaneously move all of said wires equal amounts, and adjustable exterior means connected to said mounting means for operating said mounting means and for thereby changing the relation of said grid wires to the cathode and cathode axis.

2. An electron discharge device having a cathode and an anode, a grid between said cathode and anode, said grid having wires parallel to the cathode axis, adjustable means mounting said wires movably for movement toward and away from the cathode and its axis in constant parallelism to the axis thereof, and adjustable exterior means connected to said mounting means for operating said mounting means and for thereby changing the relation of said grid wires to the cathode and cathode axis.

-3., An electron discharge device comprising a cathode and anode and, a grid having a plurality of wires parallel to the cathode axis, parallel arms pivotally supporting ends of a grid wire, said arms being pivotally mounted whereby said grid wire supported thereby is movable laterally as '4 said arms swing, and means connected with, and for swinging, one of said arms.

4. An electron discharge device comprising an axially disposed cathode, anode and grid, said 5 grid being radially expandable and contractable,

fixed plates mounting said grid, and means extending'from said plates tosaid grid and movable with respect to both said plates and grid, said means supporting the grid from the plates and providing the expanding and contracting radial adjustment for said grid.

5. An electron discharge device comprising an axially disposed cathode, anode and grid, fixed plates above and below said cathode transverse to and centered on said axis, said grid having a plurality of wires parallel to said axis, and arms extending from and pivoted to said plates and wires, the pair of arms for each said wire being parallel to each other, a movable plate, and links extending from the movable plate to the arms pivoted to one of the fixed plates whereby moving said movable plate swings said arms and shifts the said wires laterally.

6. An electron discharge device comprising an axially disposed cathode, anode and grid, fixed plates above and below said cathode transverse to and centered on said axis, said grid having a plurality of wires parallel to said axis, and arms extending from and pivoted to said plates and wires, the pair of arms for each said wire being parallel to each other, a movable plate, and links extending from the movable plate to the arms pivoted to one of the fixed plates whereby moving said movable plate swings said arms and shifts 35 'the said wires laterally, and means connected with, and for moving, said movable plate and thereby shifting all said grid wires simultaneously.

'7. An electron discharge device comprising a sealed envelope, a cathode, anode and grid there- 40 in coaxial to a common axis, said grid having a plurality of wires parallel to said axis and movable laterally for adjustment thereof toward and from the cathode, fixed plates above and below said cathode transverse to and centered on said axis, arms extending from and pivoted to said plates and wires, a, movable plate below the plate below the cathode, a stem secured to said movable plate and extending to the exterior of the envelope, and links extending from the said movable 5 plate to the arms pivoted to the said plate below the cathode, whereby axial displacement of said movable plate may be effected by said stem from the exterior of the envelope and whereby said displacement communicates movement to said arms and grid wires and moves the grid wires laterally.

0 ble laterally for adjustment thereof toward and from the cathode, fixed plates above and below said cathode transverse to and centered on said axis, arms extending from and pivoted to said plates and wires, a movable plate below the plate is below the cathode, a stem secured to said movable plate and extending to the exterior of the envelope, and links extending from the said movable plate to the arms pivoted to the said plate below the cathode, whereby axial displacement of said .70 movable plate may be effected by said stem from the exterior of the envelope and whereby said displacement Y communicates movement to said arms and grid wires and moves the grid wires laterally, and rotative screw threaded means at the exterior of said envelope connected with said stem for applying longitudinal movement to said stem.

EDGAR K. WIMPY. LEO C. WERNER.

REFERENCES CITED The following references are of record. in the file of this patent:

Number UNITED STATES PATENTS Name Date Leonard, Jr Dec. 24, 1935 Hartley Jan. 11, 1927 Kuhle et a1 May 11, 1937 Manthorne July 25, 1939 Bowles Dec. 11, 1934 

